From milliken police FB, I was able to get in this way to top off my saltwater tanks.
There is now one route to get in and out of Milliken. You must take WCR 46.5 (Green Street) west to WCR 19. WCR 19 south to WCR 38. WCR 38 west to WCR 13. WCR 13 south to WCR 34 or WCR 24 west to I-25. The main roads out of town (HWY 60, Hwy 257, and Two Rivers Parkway remain closed at this time and an estimated time for them to be reopened is unknown. In many cases the roads are badly damaged or washed away.
Pretty easy as many of the turns are blocked.